转子槽数对无刷交流励磁机的空载噪声影响

Effect of Number of Rotor Slots on No-load Noise of Brushless AC Exciter

为减少无刷交流励磁机的电磁噪声,提出一种无刷交流励磁机径向电磁力和交变弯曲力矩的解析模型。根据磁导法,得到空载气隙磁场的解析表达式,进而推导出径向电磁力和交变弯曲力矩的表达式,得到励磁机电磁噪声的主要阶次和转子槽数的关系。通过增加转子槽数可以有效削弱主极磁场和一阶齿谐波引起的噪声,多物理耦合有限元仿真和傅里叶方法验证了结果。

In order to reduce the electromagnetic noise of brushless AC exciter,an analytical model of radial electromagnetic force and alternating bending moment of brushless AC exciter was proposed.According to the magnetic permeability method,the analytical expression of the no-load air gap magnetic field was obtained,and then the expressions of the radial electromagnetic force and the alternating bending moment were derived to obtain the relationship between the main order of the electromagnetic noise of the exciter and the number of rotor slots.The noise caused by the main pole magnetic field and the first-order tooth harmonics could be effectively attenuated by increasing the number of rotor slots,and the results were verified by multiphysics coupled finite element simulation and Fourier method.